Despite extensive research, the mechanisms of atrial fibrillation are still not clear. The central
scientific question is what are the necessary conditions for the induction and maintenance of
atrial fibrillation. This thesis presents simulation-, clinical- and experimental- studies of atrial
fibrillation beginning from simplified to complex models. Main topics are the understanding
of influence parameters of signal recordings, understanding the impact of fibrosis on the
development of AF sources, and the development of new methods and catheter designs for
the detection of AF sources.